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Choquet game

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353: 407: 986: 928: 1040: 704: 848: 651: 578: 1088: 780: 532: 875: 605: 265: 238: 211: 184: 133: 106: 1060: 744: 724: 496: 462: 434: 157: 77: 53: 468:. (Note that it is possible that neither player has a winning strategy.) Thus every Choquet space is Baire. On the other hand, there are Baire spaces (even 270: 358: 1181: 1154: 1123: 933: 1202: 880: 991: 1207: 656: 1093: 790: 807: 610: 537: 1066: 1177: 1150: 1140: 1119: 749: 501: 56: 28:, who was in 1969 the first to investigate such games. A closely related game is known as the 1171: 1144: 441: 21: 853: 583: 243: 216: 189: 162: 111: 797: 469: 82: 25: 1045: 729: 709: 481: 447: 419: 413: 142: 62: 38: 786:. Every strong Choquet space is a Choquet space, although the converse does not hold. 1196: 794: 348:{\displaystyle U_{0}\supseteq V_{0}\supseteq U_{1}\supseteq V_{1}\supseteq U_{2}...} 1113: 437: 472: 1063: 136: 267:, etc. The players continue this process, constructing a sequence 402:{\displaystyle \bigcap \limits _{i=0}^{\infty }U_{i}=\emptyset } 1115:
Lectures on Analysis: Integration and topological vector spaces
981:{\displaystyle \operatorname {cl} (V_{i})\subseteq V_{i-1}} 475:
ones) that are not Choquet spaces, so the converse fails.
1176:. Springer Science & Business Media. pp. 43–45. 804:
are strong Choquet. (In the first case, Player II, given
464:
in which Player II has a winning strategy is called a
1069: 1048: 994: 936: 883: 856: 810: 752: 732: 712: 659: 613: 586: 540: 534:, is defined similarly, except that Player I chooses 504: 484: 450: 422: 361: 273: 246: 219: 192: 165: 145: 114: 85: 65: 41: 923:{\displaystyle \operatorname {diam} (V_{i})<1/i} 1146:The Descriptive Set Theory of Polish Group Actions 1082: 1062:.) Any subset of a strong Choquet space that is a 1054: 1035:{\displaystyle \left\{x_{i}\right\}\to x\in V_{i}} 1034: 980: 922: 869: 842: 774: 738: 718: 698: 645: 599: 572: 526: 490: 456: 428: 401: 347: 259: 232: 205: 178: 151: 127: 100: 71: 47: 746:in which Player II has a winning strategy for 409:then Player I wins, otherwise Player II wins. 8: 1149:. Cambridge University Press. p. 59. 108:, is defined as follows: Player I chooses 1092:is strong Choquet. Metrizable spaces are 1074: 1068: 1047: 1026: 1003: 993: 966: 950: 935: 912: 897: 882: 861: 855: 831: 818: 809: 757: 751: 731: 711: 690: 677: 664: 658: 634: 621: 612: 591: 585: 561: 548: 539: 509: 503: 483: 449: 421: 387: 377: 366: 360: 330: 317: 304: 291: 278: 272: 251: 245: 224: 218: 197: 191: 170: 164: 144: 119: 113: 84: 64: 40: 1096:if and only if they are strong Choquet. 1104: 7: 699:{\displaystyle x_{i}\in U_{i},V_{i}} 416:that a non-empty topological space 363: 396: 378: 14: 1173:Classical Descriptive Set Theory 444:. A nonempty topological space 440:if and only if Player I has no 1013: 956: 943: 903: 890: 837: 811: 769: 763: 640: 614: 567: 541: 521: 515: 95: 89: 1: 843:{\displaystyle (x_{i},U_{i})} 646:{\displaystyle (x_{1},U_{1})} 573:{\displaystyle (x_{0},U_{0})} 240:, a non-empty open subset of 186:, a non-empty open subset of 1170:Kechris, Alexander (2012). 1083:{\displaystyle G_{\delta }} 478:The strong Choquet game of 1224: 1112:Choquet, Gustave (1969). 580:, then Player II chooses 159:, then Player II chooses 775:{\displaystyle G^{s}(X)} 607:, then Player I chooses 527:{\displaystyle G^{s}(X)} 213:, then Player I chooses 1203:Descriptive set theory 1084: 1056: 1036: 982: 924: 871: 844: 791:complete metric spaces 776: 740: 726:. A topological space 720: 700: 647: 601: 574: 528: 492: 458: 430: 403: 382: 349: 261: 234: 207: 180: 153: 129: 102: 73: 59:. The Choquet game of 49: 1094:completely metrizable 1085: 1057: 1037: 983: 925: 872: 870:{\displaystyle V_{i}} 845: 777: 741: 721: 701: 648: 602: 600:{\displaystyle V_{0}} 575: 529: 493: 459: 431: 404: 362: 350: 262: 260:{\displaystyle V_{0}} 235: 233:{\displaystyle U_{1}} 208: 206:{\displaystyle U_{0}} 181: 179:{\displaystyle V_{0}} 154: 130: 128:{\displaystyle U_{0}} 103: 74: 50: 1067: 1046: 992: 988:. Then the sequence 934: 881: 854: 808: 784:strong Choquet space 750: 730: 710: 657: 611: 584: 538: 502: 482: 448: 420: 359: 271: 244: 217: 190: 163: 143: 112: 101:{\displaystyle G(X)} 83: 63: 39: 30:strong Choquet game 1118:. W. A. Benjamin. 1080: 1052: 1032: 978: 920: 867: 840: 772: 736: 716: 696: 643: 597: 570: 524: 488: 454: 426: 399: 345: 257: 230: 203: 176: 149: 125: 98: 69: 45: 1208:Topological games 1055:{\displaystyle i} 739:{\displaystyle X} 719:{\displaystyle i} 653:, etc, such that 491:{\displaystyle X} 457:{\displaystyle X} 429:{\displaystyle X} 412:It was proved by 152:{\displaystyle X} 72:{\displaystyle X} 57:topological space 48:{\displaystyle X} 1215: 1188: 1187: 1167: 1161: 1160: 1139:Becker, Howard; 1136: 1130: 1129: 1109: 1089: 1087: 1086: 1081: 1079: 1078: 1061: 1059: 1058: 1053: 1041: 1039: 1038: 1033: 1031: 1030: 1012: 1008: 1007: 987: 985: 984: 979: 977: 976: 955: 954: 929: 927: 926: 921: 916: 902: 901: 876: 874: 873: 868: 866: 865: 849: 847: 846: 841: 836: 835: 823: 822: 781: 779: 778: 773: 762: 761: 745: 743: 742: 737: 725: 723: 722: 717: 705: 703: 702: 697: 695: 694: 682: 681: 669: 668: 652: 650: 649: 644: 639: 638: 626: 625: 606: 604: 603: 598: 596: 595: 579: 577: 576: 571: 566: 565: 553: 552: 533: 531: 530: 525: 514: 513: 497: 495: 494: 489: 463: 461: 460: 455: 442:winning strategy 435: 433: 432: 427: 408: 406: 405: 400: 392: 391: 381: 376: 354: 352: 351: 346: 335: 334: 322: 321: 309: 308: 296: 295: 283: 282: 266: 264: 263: 258: 256: 255: 239: 237: 236: 231: 229: 228: 212: 210: 209: 204: 202: 201: 185: 183: 182: 177: 175: 174: 158: 156: 155: 150: 134: 132: 131: 126: 124: 123: 107: 105: 104: 99: 78: 76: 75: 70: 54: 52: 51: 46: 22:topological game 1223: 1222: 1218: 1217: 1216: 1214: 1213: 1212: 1193: 1192: 1191: 1184: 1169: 1168: 1164: 1157: 1138: 1137: 1133: 1126: 1111: 1110: 1106: 1102: 1070: 1065: 1064: 1044: 1043: 1022: 999: 995: 990: 989: 962: 946: 932: 931: 893: 879: 878: 857: 852: 851: 827: 814: 806: 805: 801: 753: 748: 747: 728: 727: 708: 707: 686: 673: 660: 655: 654: 630: 617: 609: 608: 587: 582: 581: 557: 544: 536: 535: 505: 500: 499: 480: 479: 446: 445: 418: 417: 383: 357: 356: 326: 313: 300: 287: 274: 269: 268: 247: 242: 241: 220: 215: 214: 193: 188: 187: 166: 161: 160: 141: 140: 115: 110: 109: 81: 80: 61: 60: 55:be a non-empty 37: 36: 26:Gustave Choquet 12: 11: 5: 1221: 1219: 1211: 1210: 1205: 1195: 1194: 1190: 1189: 1182: 1162: 1155: 1141:Kechris, A. S. 1131: 1124: 1103: 1101: 1098: 1077: 1073: 1051: 1029: 1025: 1021: 1018: 1015: 1011: 1006: 1002: 998: 975: 972: 969: 965: 961: 958: 953: 949: 945: 942: 939: 919: 915: 911: 908: 905: 900: 896: 892: 889: 886: 864: 860: 839: 834: 830: 826: 821: 817: 813: 799: 771: 768: 765: 760: 756: 735: 715: 693: 689: 685: 680: 676: 672: 667: 663: 642: 637: 633: 629: 624: 620: 616: 594: 590: 569: 564: 560: 556: 551: 547: 543: 523: 520: 517: 512: 508: 487: 453: 425: 414:John C. Oxtoby 398: 395: 390: 386: 380: 375: 372: 369: 365: 344: 341: 338: 333: 329: 325: 320: 316: 312: 307: 303: 299: 294: 290: 286: 281: 277: 254: 250: 227: 223: 200: 196: 173: 169: 148: 135:, a non-empty 122: 118: 97: 94: 91: 88: 68: 44: 13: 10: 9: 6: 4: 3: 2: 1220: 1209: 1206: 1204: 1201: 1200: 1198: 1185: 1183:9781461241904 1179: 1175: 1174: 1166: 1163: 1158: 1156:9780521576055 1152: 1148: 1147: 1142: 1135: 1132: 1127: 1125:9780805369601 1121: 1117: 1116: 1108: 1105: 1099: 1097: 1095: 1091: 1075: 1071: 1049: 1027: 1023: 1019: 1016: 1009: 1004: 1000: 996: 973: 970: 967: 963: 959: 951: 947: 940: 937: 917: 913: 909: 906: 898: 894: 887: 884: 862: 858: 832: 828: 824: 819: 815: 803: 796: 792: 789:All nonempty 787: 785: 766: 758: 754: 733: 713: 691: 687: 683: 678: 674: 670: 665: 661: 635: 631: 627: 622: 618: 592: 588: 562: 558: 554: 549: 545: 518: 510: 506: 485: 476: 474: 471: 467: 466:Choquet space 451: 443: 439: 423: 415: 410: 393: 388: 384: 373: 370: 367: 342: 339: 336: 331: 327: 323: 318: 314: 310: 305: 301: 297: 292: 288: 284: 279: 275: 252: 248: 225: 221: 198: 194: 171: 167: 146: 138: 120: 116: 92: 86: 66: 58: 42: 33: 31: 27: 23: 19: 1172: 1165: 1145: 1134: 1114: 1107: 788: 783: 782:is called a 477: 465: 411: 34: 29: 24:named after 18:Choquet game 17: 15: 438:Baire space 137:open subset 1197:Categories 1100:References 877:such that 850:, chooses 473:metrizable 1076:δ 1020:∈ 1014:→ 971:− 960:⊆ 941:⁡ 888:⁡ 671:∈ 470:separable 397:∅ 379:∞ 364:⋂ 324:⊇ 311:⊇ 298:⊇ 285:⊇ 1143:(1996). 1042:for all 706:for all 795:compact 1180:  1153:  1122:  802:spaces 436:is a 355:. If 20:is a 1178:ISBN 1151:ISBN 1120:ISBN 930:and 907:< 885:diam 793:and 35:Let 16:The 1090:set 139:of 1199:: 938:cl 498:, 79:, 32:. 1186:. 1159:. 1128:. 1072:G 1050:i 1028:i 1024:V 1017:x 1010:} 1005:i 1001:x 997:{ 974:1 968:i 964:V 957:) 952:i 948:V 944:( 918:i 914:/ 910:1 904:) 899:i 895:V 891:( 863:i 859:V 838:) 833:i 829:U 825:, 820:i 816:x 812:( 800:2 798:T 770:) 767:X 764:( 759:s 755:G 734:X 714:i 692:i 688:V 684:, 679:i 675:U 666:i 662:x 641:) 636:1 632:U 628:, 623:1 619:x 615:( 593:0 589:V 568:) 563:0 559:U 555:, 550:0 546:x 542:( 522:) 519:X 516:( 511:s 507:G 486:X 452:X 424:X 394:= 389:i 385:U 374:0 371:= 368:i 343:. 340:. 337:. 332:2 328:U 319:1 315:V 306:1 302:U 293:0 289:V 280:0 276:U 253:0 249:V 226:1 222:U 199:0 195:U 172:0 168:V 147:X 121:0 117:U 96:) 93:X 90:( 87:G 67:X 43:X

Index

topological game
Gustave Choquet
topological space
open subset
John C. Oxtoby
Baire space
winning strategy
separable
metrizable
complete metric spaces
compact
T2 spaces
G δ {\displaystyle G_{\delta }} set
completely metrizable
Lectures on Analysis: Integration and topological vector spaces
ISBN
9780805369601
Kechris, A. S.
The Descriptive Set Theory of Polish Group Actions
ISBN
9780521576055
Classical Descriptive Set Theory
ISBN
9781461241904
Categories
Descriptive set theory
Topological games

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